A legume-specific novel type of phytosulfokine, PSK-delta, promotes nodulation by enhancing nodule organogenesis

• 全文链接
• 请求原文

作   者：

Yu, Liangliang;  Di, Qi;  Zhang, Danping;  Liu, Yumin;  Li, Xiaolin;  Mysore, Kirankumar S.;  Wen, Jiangqi;  Yan, Junhui;  Luo, Li; 

作者机构：

Chinese Acad Sci;  Oklahoma State Univ;  Shanghai Univ; 

关键词：

Medicago truncatula;  PSK-delta;  LATERAL ROOT;  PRECURSOR;  PEPTIDE GROWTH-FACTOR;  RHIZOBIAL INFECTION;  Legume species;  ALPHA;  symbiotic nodulation;  phytosulfokine;  GENE;  Rhizobium-legume symbiosis;  MEDICAGO-TRUNCATULA;  nodule organogenesis;  TYROSYLPROTEIN SULFOTRANSFERASE;  MESOPHYLL-CELLS;  ARABIDOPSIS; 

期刊名称：

Journal of Experimental Botany

i s s n：

0022-0957

年卷期：

2022 年 73 卷 8 期

页   码：

2698-2713

页   码：

摘   要：

Phytosulfokine-alpha (PSK-alpha), a tyrosine-sulfated pentapeptide with the sequence Y(SO3)IY(SO3)TQ, is widely distributed across the plant kingdom and plays multiple roles in plant growth, development, and immune response. Here, we report a novel type of phytosulfokine, PSK-delta, and its precursor proteins (MtPSK delta, LjPSK delta, and GmPSK delta 1), specifically from legume species. The sequence YSO3IYSO3TN of sulfated PSK-delta peptide is different from PSK-alpha at the last amino acid. Expression pattern analysis revealed PSK-delta-encoding precursor genes to be expressed primarily in legume root nodules. Specifically, in Medicago truncatula, MtPSK delta expression was detected in root cortical cells undergoing nodule organogenesis, in nodule primordia and young nodules, and in the apical region of mature nodules. Accumulation of sulfated PSK-delta peptide in M. truncatula nodules was detected by LC/MS. Application of synthetic PSK-delta peptide significantly increased nodule number in legumes. Similarly, overexpression of MtPSK delta in transgenic M. truncatula markedly promoted symbiotic nodulation. This increase in nodule number was attributed to enhanced nodule organogenesis induced by PSK-delta. Additional genetic evidence from the MtPSK delta mutant and RNA interference assays suggested that the PSK-delta and PSK-alpha peptides function redundantly in regulating nodule organogenesis. These results suggest that PSK-delta, a legume-specific novel type of phytosulfokine, promotes symbiotic nodulation by enhancing nodule organogenesis.